Why is this the only moba company that doesn't have a weekly game mode rotation?

Straight up every other moba has so many more modes that are fun as hell and would make league less stale. 100k gold at start. max level at start. demacia only. noxus only. tanks only. i could go on. please riot this is so easy to do its not even funny instead of spending 100k on youtube ads give people a reason to come back once a week. hell even your cats vs dogs was a missed game mode one team gets cats or dogs then you fight it out only using those champions....